Squid's beak offers insight into improving human prosthetics

Randolph E. Schmid, Associated Press

Published
4:00 am PDT, Friday, March 28, 2008

In this photo released by Tasmania Parks and Wildlife Service, a giant squid is seen after it washed up onto Ocean Beach in Strahan, Tasmania, Tuesday, July, 10. 2007. The squid, measuring 1 meter (3 feet) across at its widest point and 8 meters (26 feet) from the tip of its body to the end of its tentacles, was found early Wednesday by a beachcomber at Ocean Beach on the island state of Tasmania's west coast. (AP Photo/Tasmania Parks and Wildlife Service, HO) less

In this photo released by Tasmania Parks and Wildlife Service, a giant squid is seen after it washed up onto Ocean Beach in Strahan, Tasmania, Tuesday, July, 10. 2007. The squid, measuring 1 meter (3 feet) ... more

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In this photo released by Tasmania Parks and Wildlife Service, a giant squid is seen after it washed up onto Ocean Beach in Strahan, Tasmania, Tuesday, July, 10. 2007. The squid, measuring 1 meter (3 feet) across at its widest point and 8 meters (26 feet) from the tip of its body to the end of its tentacles, was found early Wednesday by a beachcomber at Ocean Beach on the island state of Tasmania's west coast. (AP Photo/Tasmania Parks and Wildlife Service, HO) less

In this photo released by Tasmania Parks and Wildlife Service, a giant squid is seen after it washed up onto Ocean Beach in Strahan, Tasmania, Tuesday, July, 10. 2007. The squid, measuring 1 meter (3 feet) ... more

Photo: Xx

Squid's beak offers insight into improving human prosthetics

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The razor-sharp beaks that giant squid use to attack whales - and maybe even Captain Nemo's submarine - might one day lead to improved artificial limbs for people.

That deadly beak may be a surprise to many people, and has long posed a puzzle for scientists. They wonder how a creature without any bones can operate it without hurting itself.

Now, researchers at UC Santa Barbara report in today's edition of the journal Science that they have an explanation.

The beak, made of hard chitin and other materials, changes density gradually from the hard tip to a softer flexible base where it attaches to the muscle around the squid's mouth, the researchers found. That means the beak can chomp away at fish for dinner, but the hard material doesn't press or rub directly against the squid's softer tissues.

Herbert Waite, a professor in the university's department of molecular, cellular and developmental biology and co-author of the paper, said such materials could have broad applications in biomedical materials.

"Lots of useful information could come out of this for implant materials, for example. Interfaces between soft and hard materials occur everywhere," he said in a telephone interview.

Frank Zok, associate chair of the department of materials, said he had always been skeptical of whether there is any real advantage to materials that change their properties gradually from one part to another, "but the squid beak turned me into a believer."

"If we could reproduce the property gradients that we find in squid beak, it would open new possibilities for joining materials," Zok said in a statement. "For example, if you graded an adhesive to make its properties match one material on one side and the other material on the other side, you could potentially form a much more robust bond."

Messersmith, who was not part of the research team, noted that hard medical implants made of metal or ceramic are often imbedded in soft tissues.

Ali Miserez, a UC Santa Barbara researcher and co-author of the paper, suggested the research could point the way to new types of medical materials.

"We could maybe imagine creating a full prosthesis that mimics the chemistry of the beak, so that it matches the elasticity of cartilage on one side and, on the other side, you could create a material which is very stiff and abrasion resistant," he said in an interview provided by Science.

Waite described the squid beak as like placing an X-Acto blade in a block of fairly firm Jell-O and then trying to use it to chop celery.

The base of the blade would damage the gelatin, but because of the change in density the base of the beak doesn't damage the squid, he said. The squid solves the problem by changing the beak composition progressively, rather than abruptly, so that its tip can pierce prey without harming the squid in the process.